Sweet Corn

Fall armyworm (FAW) has begun to appear in coastal areas.  We have low level infestations of this pest in whorl stage sweet corn in Monmouth County, and reports of early populations in Cape May, where FAW was a significant problem last season.  This pest is capable of significant injury to sweet corn plants, resulting in severe stunting and failure to produce viable ears.  Importantly, FAW favors whorl, and even seedling stage sweet corn for egg laying so it is critical that growers check even recently emerged plantings for signs of FAW injury.

Newly hatched FAW larvae cause holes and scratches on leaves that are similar to European corn borer (ECB) feeding, except that they tend to be more concentrated and always lead down into the whorl  (see photos at left).  As the larvae grow, the feeding becomes more destructive, with large ragged holes and obvious droppings deposited in the whorl (see photo at right). 

We will provide updates on new FAW appearances and severity as reports come in.  FAW are resistant to synthetic pyrethroids.  Effective sprays should include IRAC grp. 5 (spinosyns) or IRAC grp. 28 (diamides).  The carbamate (IRAC grp. 1A) Lannate is also still effective.  Sufficient water should be used in the applications to allow the solution to penetrate the layer of droppings that may have formed above the caterpillar.

European corn borer (ECB) moth activity remains extremely low in areas where blacklight traps are operating in the northern and central counties.  Many plantings exhibiting no ECB injury at all.  We will report on ECB activity should numbers rebound to potentially damaging levels during the second flight.  In recent years, this later flight has not required targeted control in sweet corn.

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Sweet Corn

European corn borer (ECB) moth activity remains extremely low in areas where blacklight traps are operating in the northern and central counties.  Feeding in whorl and pre-tassel stage corn has decreased over the past week.  Many plantings exhibiting no ECB injury at all.    While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.

Look for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 7/12/23 are as follows:

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Sweet Corn

European corn borer (ECB) moth activity is extremely low in areas where blacklight traps are operating in the northern and central counties.  Feeding in whorl and pre-tassel stage corn has increased slightly over the past week, but only in a few areas.  Many plantings exhibiting no ECB injury at all.    While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.

Look for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 7/05/23 are as follows:

[Read more…]

Sweet Corn

Low numbers of European corn borer (ECB) moth activity has declined to very low levels in areas where blacklight traps are operating in the northern and central counties.  Feeding in whorl and pre-tassel stage corn has increased only slightly over the past week, with many plantings exhibiting no ECB injury at all.    While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.

Look for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 6/28/23 are as follows:

[Read more…]

Sweet Corn

Low numbers of European corn borer (ECB) moths remain active in areas where blacklight traps are operating in the northern and central counties, although feeding in whorl and pre-tassel stage corn is low and sporadic in occurrence.  The highest feeding levels are in southern Hunterdon and Monmouth counties.   ECB injury around 20% of plants infested has been found in those areas recently.  While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.   It is typical for feeding percentages to rise as the moth catch declines.  We expect feeding to increase for the next 1-2 weeks before peaking.

Look for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 6/21/23 are as follows:

[Read more…]

Sweet Corn

Low numbers of European corn borer (ECB) moths continue to be captured in a few of the remaining blacklight traps in the northern and central counties, although feeding in whorl and pre-tassel stage corn is low and sporadic in occurrence.  The highest feeding levels are in southern Hunterdon County.   ECB injury over 12% of plants infested has been found in that area recently.  While ECB has become something of a local phenomenon in NJ, growers should not assume that feeding is below economic levels in their area.   It is typical for feeding percentages to rise as the moth catch declines.  We expect feeding to increase for the next 1-2 weeks before peaking.

Look for the characteristic “shot-hole” type of feeding (photo  below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 6/14/23 are as follows:

[Read more…]